Propeller



Oct. 6, 1942. E. A. F. PRES SER PROPELLER Filed Jan. 23, 1941 2Sheets-Sheet 1 A fiorney M Oct. 6, 1942. E. A. F. PRESSER 2,298,021

PROPELLER Filed Jan. 23, 1941 2 Shets-Sheet 2 A iiomey Patented Oct. 6,1942 UNITED STATES PATENT OFFICE PROPELLER Eric Arnold Fritz Presser,East Chicago, Ind.

Application January 23, 1941, Serial No. 375,690v

4 Claims.

The present invention relates to new and useful improvements inpropellers adapted for either air or water propulsion and has for itsprimary object to provide means for increasin the propelling forcewithout necessitating any increase in the speed of rotation of thepropeller.

To accomplish this purpose I provide a propeller construction adapted toeliminate the usual vacuum caused at the stern of the hull of a vesselby the forward motion of the vessel when using conventional types ofpropellers, and also to create a vacuum at the nose of an airplanethrough the use of my invention and thus accelerate the movement of thevessel or airplane.

A further object of the invention is to provide a propeller of simpleand practical construction, which is of improved efliciency, relativelyinexpensive to manufacture and otherwise well adapted for the purposesfor which the same is intended.

Other objects and advantages reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming part hereof, wherein likenumerals refer to like parts throughout, and in which Figure 1 is a sideelevational view showing the propeller mounted at the front end of anairplane,

Figure 2 is a front elevational View,

Figures 3, 4, and 6 are sectional views taken respectively on the lines3-3, 4-4, 55 and 6-6 of Figure 2,

Figure 7 is a fragmentary sectional view through the hub of thepropeller, and

Figure 8 is an enlarged fragmentary front elevational view of thecentral triangularly-shaped inner blades.

Referring now to the drawings in detail, wherein I have disclosed apreferred embodiment of the invention, the numeral 5 designates thepropeller shaft, which includes the head 6 having the forwardly taperingportion 1 of square or other noncircular shape in cross section andprovided with the forwardly extending threaded stem 8.

The main or outer propeller blades are shown at 9 and include theabutting inner end portions l0 disposed at right angles to the shaft andhaving the notches l l conformably receiving the square portion 1 of theshaft, the blades being disposed in a forwardly diverging relation asshown in Figure 1.

The blades are twisted angularly as shown at l2 throughout the greaterportion of the length CJI thereof to provide the necessary traction anda porticn of the blades immediately adjacent their inner portions I'llare twisted oppositely to the portion 12 to provide a counter-pitch asshown at l2. The blades are connected by a plurality of brace wirees I3to prevent bending of the blades by wind resistance and centrifugalforce.

An inner triangular-shaped blade I4 is also provided which includesinturned ends l5 forming a base portion, said end overlying the innerends of the blades 9 and clamped under the opposite edges of a steppedfastening plate It positioned on the square section of the shaft.

A fastening plate H is also positioned on the shaft inwardly of the endsof the blades 9, and the inner and outer fastening plate and the ends oftheinner and outer blades are secured in assembled relation as a unit onthe shaft by bolts iii, to form the hub portion for the blades.

A nut l9 is then threaded on the stem 8 against a washer 20 to securethe hub on the shaft, the nut and end of the stem being provided with agroove 2| in which a U-shaped wire spring 22 isv fittedto lock thenutagainst turning.

The sides of the triangular blade M are twisted as shown at 23 at anangle to the axis of the shaft and the trailing and leading edges of thebase portion of the triangular blade are bent oppositely as shown at 24and 25 to provide a counter-pitch at the base of the inner blade [4.

When the propeller is used on an airplane, of which the fuselage isindicated at 26 in Figure 1, and with the respective blades arranged asillustrated, the base portion of the triangular blade l4 extendstransversely in advance of the nose of the fuselage so that thecounter-pitch formed by the edges 24 and 25 cooperate to draw the airfrom the nose and throw the air forwardly against the sides 23 of theinner triangular blade l4, thus to pull the air from in front of thefuselage reducing the air resistance to which the fuselage is usuallysubjected and tending to produce a vacuum to facilitate forward movementof the airplane. The inner triangular blade [4 then feeds the airlaterally to the outer blades 9, which because of their divergingrelation spreads the air radially from the path of the fuselage. Thecounter-pitch portion 12' of the blades 9 also serves to pull the airfrom the immediate vicinity of the nose of the fuselage to enlarge thevacuum area and likewise throws the air in the path of counter-pitchportion I2, functioning oppositely to pull the water inwardly from theregion of the angle between the blades 9, now diverging in backwarddirection, toward the stem to prevent the formation of the usual vacuumcaused by the forward motion of the vessel and tending to cause apressure area between hull and propeller.

It is believed the details of construction, advantages and manner of useof the device will be readily understood from the foregoing withoutfurther detailed explanation.

Having thus described the invention, what is claimed as new is:

l. A propeller comprising an inner triangularshaped blade having a baseportion extending at right angles to the axis of rotation thereof, saidbase portion having oppositely inclined leading and trailing edges andsaid inner blade having longitudinally extending converging sides and apair of outer blades extending in diverging relation from said baseportion of the inner blade. said inner blade being adapted to act onfluid in the region of the hub of the propeller to move the fluidlaterally relative to the axis of rotation of the propeller.

2. A propeller comprising an inner triangularshaped blade having a baseportion extending at right angles to the axis of rotation thereof, saidbase portion having oppositely inclined leading and trailing edges andsaid inner blade having longitudinally extending converging sides and apair of outer blades extending in diverging relation from said baseportion of the inner blade, said trailing and leading edges of the baseportion acting on fluid in the region of the base to move the samelongitudinally toward the sides of the inner blade and said sides beingadapted to move the fluid laterally.

3. A propeller comprising an inner triangularshaped blade having a baseportion extending at right angles to the axis of rotation thereof, saidbase portion having oppositely inclined leading and trailing edges andsaid inner blade having longitudinally extending converging sides, and apair of outer blades extending in diverging relation from said baseportion of the inner blade, the inner ends of said outer bladesextending transversely with respect to said base portion of the innerblade, said outer blades including oppositely inclined portionsimmediately adjacent their inner ends, said oppositely inclined portionsof the inner and outer blades cooperating to act on fluid in the regionof the hub to move the fluid into the path of the longitudinallyconverging sides of the inner blade and said longitudinally convergingsides of the inner blade acting on the fluid to throw the same into thepath of rotation of the propeller and the outer blades.

4. A propeller comprising an inner triangularshaped blade having a baseportion extending at right angles to the axis of rotation thereof, saidbase portion having oppositely inclined leading and trailing edges andsaid inner blade having longitudinally extending converging sides, and apair of outer blades extending in diverging relation from said baseportion of the inner blade, the inner ends of said outer bladesextending transversely with respect to said base portion of the innerblade, said outer blades including oppositely inclined portionsimmediately adjacent their inner ends, said oppositely inclined portionsof the inner and outer blades cooperating to act on fluid in the regionof the hub to move the fluid into the path of rotation of thelongitudinally converging sides of the inner blade tending to produce avacuum in the region of the hub upon rotation of the propeller in onedirection and tending to prevent formation of a vacuum and to produce apressure in the region of the hub when rotated in an opposite direction,and said longitudinally converging sides of the inner blade acting onthe fluid to remove the same from the path of rotation of the outerblades with the effect of forming a compression area between the hull onwhich the propeller is mounted and the propeller.

ERIC ARNOLD FRITZ PRESSER.

